Electric and plug-in hybrid vehicles include a traction battery to provide power for propulsion and accessory loads. To function effectively, the traction battery must be charged when a state of charge of the battery falls below a threshold. A charger that is connected to an external power source may be coupled to the vehicle for the purpose of charging the traction battery. The charger may connect to a charge port of the vehicle. The charger may provide a maximum battery charging current to the traction battery during charging. Conducting elements within the vehicle are designed to conduct the maximum battery charging current for an indefinite period of time without a temperature of the conducting elements rising above a predetermined temperature.